Okies, a while back I made myself a basic latex skirt (originally an attempt at a dress but the top bit was a fail). See below for what I mean:

Simple pull on- the shape in the pattern makes it naturally fishtail in the back courtesy of the curve of your backside and the tapering in of your legs

And in terms of how to make the pattern for one I've done the following super basic doc:

In terms of composing it:-Seams are 1cm- latex is meant to be tight no I have left seam allowance off- the inch or so seam allowance will cost you should do this, or add a 2cm to each measurement
-How much latex depends on your size- my backside requires at least a metre
-Best bet is to measure yourself naked, and hold the tape measure just on the skin- don't hold your breath or pull it tight
-Make the initial skirt about an inch longer than you think you will need, try it on once glued- if it needs to be shorter you can mark where to cut with a gel pen and sort it out once you take it back off
-Sadly the only way to glue it is with practice and trial and error- sorry not to be more encouraging but sometimes there are no shortcuts....